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Pairing a used Tesla Model 3 or Model Y HV pack with the Fronius Symo Gen24 Plus, Verto Plus and Symo Hybrid inverter families using BYD Battery-Box HV protocol emulation.
Direct answer. A Tesla Model 3 / Y HV pack (350–410 V nominal) works with Fronius hybrid inverters that expose the "Fronius Solar Battery" interface — Symo Gen24 Plus 6.0–10.0, Verto Plus 15.0–20.0 and the older Symo Hybrid line. The Fronius battery port accepts BYD Battery-Box HV protocol frames; the BMS-EV controller emulates that protocol on the CAN bus, so the inverter recognises the Tesla pack as a BYD HVS or HVM series battery. Battery DC voltage window on Gen24 Plus is 120–530 V, which fully contains the Tesla pack's operating range.
| Component | Status | Notes |
|---|---|---|
| Tesla Model 3 SR / LR / Performance pack | Yes | NCA and LFP chemistries |
| Tesla Model Y LR / Performance pack | Yes | Identical BMS to Model 3 |
| Fronius Symo Gen24 Plus (6.0–10.0) | Yes | BYD HV interface, three-phase |
| Fronius Primo Gen24 Plus (3.0–6.0) | Yes | Single-phase; power-limited for 400 V pack |
| Fronius Verto Plus (15.0–20.0) | Yes | Commercial three-phase, BYD HV interface |
| Fronius Symo Hybrid (3.0–5.0) | Legacy | Only with Fronius Solar Battery 4.5-12.0 module protocol emulation; end-of-life |
| Fronius Symo, Primo (non-hybrid) | No | PV-only, no battery port |
| Model | AC power | Phase | DC battery range | MPPT |
|---|---|---|---|---|
| Symo Gen24 Plus 6.0 | 6.0 kW | 3-phase | 120–530 V | 2 |
| Symo Gen24 Plus 8.0 | 8.0 kW | 3-phase | 120–530 V | 2 |
| Symo Gen24 Plus 10.0 | 10.0 kW | 3-phase | 120–530 V | 2 |
| Primo Gen24 Plus 3.0 | 3.0 kW | 1-phase | 120–530 V | 2 |
| Primo Gen24 Plus 4.0 | 4.0 kW | 1-phase | 120–530 V | 2 |
| Primo Gen24 Plus 5.0 | 5.0 kW | 1-phase | 120–530 V | 2 |
| Primo Gen24 Plus 6.0 | 6.0 kW | 1-phase | 120–530 V | 2 |
| Verto Plus 15.0 | 15.0 kW | 3-phase | 200–800 V | 3 |
| Verto Plus 20.0 | 20.0 kW | 3-phase | 200–800 V | 3 |
The Tesla Model 3 / Y pack operates between 300 V (deep discharge) and 415 V (full charge, NCA). The Fronius Gen24 Plus battery input accepts 120–530 V DC; the Verto Plus commercial model extends this to 200–800 V. Tesla's operating window sits inside both. For maximum inverter efficiency (~97.5 % on Gen24 Plus), keep pack SoC between 20 % and 90 % where the pack voltage stays in the 340–405 V band.
Fronius firmware supports the BYD Battery-Box HV protocol as its primary third-party battery interface. The BMS-EV controller advertises itself as a BYD HVS module stack:
| Data | Source (Tesla BMS) | Target (BYD HV frame) |
|---|---|---|
| Pack voltage | 0x132 byte 0–1 | 0x110 byte 0–1 |
| Pack current | 0x132 byte 2–3 | 0x110 byte 2–3 |
| SoC | 0x33A byte 5 | 0x150 byte 0 |
| Max cell voltage | 0x312 byte 0–1 | 0x210 byte 0–1 |
| Min cell voltage | 0x312 byte 2–3 | 0x210 byte 2–3 |
| Max cell temperature | 0x312 byte 3 | 0x220 byte 0 |
| Charge current limit | Computed from BMS | 0x130 byte 4–5 |
| Discharge current limit | Computed from BMS | 0x130 byte 6–7 |
| Module count / topology | Injected by BMS-EV | 0x250 (advertises 4 × HVS 2.56 kWh modules) |
Engineering values below are examples. Final conductor cross-section and protective-device sizing must be calculated for the actual pack, maximum current, cable length, installation method, ambient temperature and applicable local standards (IEC 60364-7-712, VDE-AR-N 4105, NEC 690).
The Symo Gen24 Plus 10.0 achieves the best measured round-trip in this pack voltage band, at approximately 92 % AC-in to AC-out (including battery losses). The Primo Gen24 Plus single-phase models are ~1 % lower due to more conversion stages.
Legacy option only. The Symo Hybrid uses the older Fronius Solar Battery interface with a different CAN framing. A separate BMS-EV firmware variant exists but this inverter family is end-of-life and not recommended for new installations.
Yes, if the inverter is ordered with the PV Point or Full Backup option. The BMS-EV controller reports the required charge/discharge limits so the Fronius firmware can size backup load draw correctly.
Nothing critical — Solar.web is a monitoring service. Inverter and battery continue to operate autonomously via the local BAT-CAN link. Only historical logging and remote diagnostics are affected.
The controller has a USB-C service port. Fronius does not need to be taken offline; disconnect the CAN cable, plug in a laptop, run the BMS-EV updater tool, reconnect. Total downtime ~2 minutes; the inverter reconnects the battery automatically.
Not natively. The Verto Plus has one battery DC input. Two packs must be paralleled on the DC bus with strict SoC matching. This is unusual; for larger installations use two Verto Plus units, each with its own pack and controller.
The Fronius side needs no change — it accepts whatever charge voltage limit the battery reports. The BMS-EV controller firmware, however, is chemistry-specific and must be ordered as LFP.